Currently it is known to deposit a spacer frame or a spacer profile on a glass pane and then mate the assembly thus formed to a second glass pane and seal it along the entire outer peripheral region so as to constitute the so-called insulating glazing unit or double glazing unit. The operation can also be a multiple one in order to obtain the insulating glazing unit constituted by three glass panes and two spacer frames or profiles, as well as n (4 or more) glass panes and n−1 spacer frames or profiles. The operation can also relate to glass panes that have different dimensions despite belonging to the same insulating glazing unit, so as to obtain an offset between their edges, which is necessary for mating with a particular type of door or window, i.e., the one that constitutes the so-called continuous glazing or so-called structural glazing. Frequently, the spacer frame or, more correctly, the profile that constitutes it, has a hollow rectangular transverse cross-section and is coated, on its sides that adhere to the glass panes, with a butyl sealant, and is also bevelled toward the outside of the double-glazing unit in order to accommodate a larger quantity of sealant. The spacer frame can also be constituted by a continuous profile made of expanded synthetic material which is coated, on its sides, with an acrylic adhesive and optionally with a butyl sealant.
Currently it is increasingly frequent to replace the air contained in the volume formed by the glass panes and by the spacer frame, a volume known as “chamber”, with a gas having more effective thermal insulation characteristics than air. This is increasingly topical in view of the requirements of technical laws related to energy saving, and the present invention therefore arises specifically to solve some method- and device-related aspects that are inadequate according to the background art available up to now.
In order to better understand the configuration of the insulating glazing unit in the combination of its components, such as the glass panes and the spacer frame or spacer profile, some concepts related to the intermediate components themselves, i.e., the glass pane 2 and the spacer profile or frame 3, and the final product, i.e., the insulating glazing unit 1, are described in greater detail hereafter, with the assumption that the subsequent use of the insulating glazing unit, i.e., as a component of the door or window or of continuous glazing or structural glazing, is known.
In order to provide a more clear description, the final product will be described and then its forming components, with reference to FIGS. 1A-1I.
The insulating glazing unit 1 is constituted by the composition of two or more glass panes 2, which are separated by one or more spacer frames 3, which are generally hollow and finely perforated on the face that is directed inward; the spacer frames contain hygroscopic material 4 in their hollow part and are provided on the lateral faces with a butyl sealant 5 (which constitutes the so-called first seal) and the chamber (or chambers) delimited by the glass panes 2 and by the spacer frame (spacer frames) 3 are able to contain air or gas or mixtures of gases that give the double-glazing unit particular properties, for example thermally insulating and/or soundproofing properties. Recently, use has become widespread also of a spacer profile 3 that has a substantially rectangular cross-section and is made of expanded synthetic material (by way of non-limiting example: silicone and EPDM), which incorporates the hygroscopic material in its mass.
The joint between the glass panes 2 and the spacer frame (frames) 3 is achieved by means of two levels of sealing: the first one 5 is intended to provide tightness and initial bonding between such components and affects, i.e. is applied on, the lateral surfaces of the frame and the portions of the adjacent glazing units, already mentioned earlier; the second one 6 is intended to provide final cohesion among the components and mechanical strength of the joint among them and affects, i.e. is applied at, the compartment constituted by the outer surface of the spacer frame 3 and by the faces of the glass panes 2 up to their edge. In the case of a spacer profile 3 made of expanded synthetic material, the first level of sealing is replaced with, or integrated by, an adhesive material, for example an acrylic one, which is already spread onto the lateral faces of such spacer profile 3 and is covered by a removable protective film.
The glass panes 2 used in the composition of the insulating glazing unit 1 can have different configurations depending on the use of such unit: for example, the outer pane (outer with respect to the building) can be normal or reflective (to limit the heat input during summer months) or laminated/armored (for intrusion prevention/vandalism prevention functions) or laminated/tempered (for safety functions) or combined (for example reflective and laminated, to obtain a combination of properties); the inner pane (inner with respect to the building) can be normal or of the low-emissivity type (in order to limit the dispersion of heat during winter months) or laminated/tempered (for safety functions) or combined (for example of the low-emissivity type and laminated to obtain a combination of properties). In particular, the outer glass pane 2M can be larger than the inner one (ones) 2m along the entire extension of the perimeter or only on one side or only on some sides.
Among the types of glass pane referenced above, the so-called laminated, reinforced and tempered ones have the characteristic, or rather the problem, of not being sufficiently planar, and this makes filling with gas difficult, at least according to known methods.
The simple summary presented above makes it already evident that a manufacturing line for obtaining the insulating glazing unit product 1 requires many processes in sequence and in particular comprises filling with a gas other than air, to which the present application relates in detail, particularly to solve the drawback of the non-planarity of the glass panes that constitute the insulating glazing unit 1.
The processes for producing the insulating glazing unit 1, each requiring a corresponding and particular machine to be arranged in series with respect to the other complementary ones, are, by way of non-limiting example and at the same time not all necessary, the following:                edging on the peripheral face of the pane to remove any coatings (generally of the type obtained with nanotechnology techniques) in order to allow and maintain over time the bond of the sealants;        beveling of the sharp edges of the glass pane, both to eliminate edge defects introduced by the cutting operation and to reduce the risks of injury in subsequent handling both of the glass panes 2 and of the insulating glazing unit 1;        washing of the individual glass panes, with an alternation of inner pane/outer pane (the orientation being the one defined earlier);        application of the spacer frame: the spacer frame 3 manufactured beforehand, filled with hygroscopic material 4 that is intended to absorb the moisture incorporated within the chamber during the manufacturing process and any moisture that might penetrate subsequently, and covered on its lateral faces with a thermoplastic sealant 5 which has tightness-providing functions, in machines that are external with respect to the production line of the insulating glazing unit 1, is applied to one of the panes, typically the second one, that constitute the insulating glazing unit 1 in an appropriately provided station of the line for production of the insulating glazing unit 1;        filling with gas, mating and pressing of the assembly of the panes 2 and the frame (frames) 3.        Second sealing of the assembly of the components: glass panes 2, spacer frame (frames) 3, at the perimeter.        
One of the most widespread solutions for replacing the air of a glazing unit with a gas that has superior thermal insulation properties, with reference to FIGS. 2 and 10, is to perform the process during the step for mating the glass panes 2 and the spacer frame or frames 3 (in the case of multi-chamber insulating glazing units). This occurs, as is known, in the machine commonly known as “coupling/pressing section with gas filling”. Such machine is constituted substantially by two beds which are slightly inclined with respect to the vertical plane, one bed 21 being fixed and aligned with the conveyors for conveying the glass panes 2 and the insulating glazing unit 1 and the other bed 22 being movable along a direction z1 that is perpendicular to such beds. The movable bed, provided with a row of suckers that are distributed over the entire bed, approaches the fixed bed, where the first glass pane 2 had been positioned earlier until it rested, even forcefully so as to strengthen them, against such glass pane and capture it by means of the activated suckers. The movable bed is then moved away from the fixed bed, and with it, the first glass pane until a space equal to the space occupation of the second glass pane that includes the spacer frame 3, which adheres to the pane by way of the first butyl sealant, plus the amount of a gap that is designed for the subsequent inflow of the gas, is cleared. Such frame adheres to the pane by way of the first, butyl sealant, plus the amount of a gap that is designed for the subsequent inflow of the gas. As the second glazing unit, which is indeed provided with a spacer frame, it is arranged by means of the conveyors on the fixed bed, suitable known mechanisms approach the manifold to introduce the gas at the base of the elements that constitute the insulating glazing unit 1 and other likewise known mechanisms provide two vertical sealing barriers at the sides of the elements that constitutes the insulating glazing unit 1, albeit with a non-rectangular shape. Then the gas is injected, and then the movable bed 22 closes toward the fixed bed 21, providing the coupling of the glass panes 2 and of the spacer 3 and simultaneous pressing. In this manner, the gas remains trapped within the insulating glazing unit 1. Thereafter the evacuation of the insulating glazing unit 1 that contains the gas other than air begins; in the case of an insulating glazing unit 1 constituted by more than two glass panes 2 (typically three) and more than one spacer frame 3 (typically two), the machine, before evacuating the insulating glazing unit 1, composed as in the steps described above, performs an additional cycle, i.e., the movable bed reopens, as mentioned above, waits for the arrangement of a third glass pane 2 provided with a second spacer frame 3, approaches it, as mentioned above, and after insertion of the gas it performs a second coupling and a second pressing. The procedure can be repeated in the case of quadruple glazing, et cetera.
The process described above can be performed by the respective machine automatically or semiautomatically.
The prior art regarding the field and describing machines and methods for filling an insulating glazing unit 1 with a gas other than air, does not appear to lead to a fully satisfactory solution for correct filling with gas in the case of glass panes 2 that are not sufficiently planar.
This aspect of the non-planarity of the glass panes 2 therefore constitutes one of the greatest current problems in the fabrication of glazing units with commercially available machines, since it compromises their results as regards the concentration of contained gas and the gas consumption. While inexpensive argon gas was used predominantly in the past, currently, in order to achieve far more efficient thermal insulations, more expensive gases, such as krypton and xenon, are used, and therefore the waste of gas during the filling step is no longer affordable (if the cost of argon is 1, krypton and xenon respectively cost 100 and 400).
Prior documents belonging to the background art pertinent to the invention comprise:                EP0674086 B2 and corresponding similar EP0674085 B1 and EP0674087 B1, in the name of Lisec Peter, related to a method and a device for filling the insulating glazing unit with a gas other than air through its lower edge 1d by resorting to a particular configuration for the seal against the edges of the glass panes and for injecting gas (parallel to the beds of the coupling/pressing/gas filling section);        WO 2006/002975 A1, in the name of Lenhardt Karl, related to a method and a device for filling the insulating glazing unit with a gas other than air through its lower edge 1d by resorting to a particular configuration for the seal against the edges of the glass panes and for injecting gas (at right angles to the beds of the coupling/pressing/gas filling section).        
The background art available does not solve the problem related to the non-planarity of glass panes. It is also not helpful with reference to the possibility to fill the insulating glazing units 3, whose glass panes 2M and 2m that compose them are not aligned along the base 1d. 